There are major fears that a bad batch of drugs has entered the market following fatal and near-fatal incidents among young people.

Gardaí are aware of reports that some youngsters have been unknowingly ingesting poor quality, or highly potent substances at festivals, debutant balls and house parties.

It has emerged a 21-year-old man from Co Galway is fighting for his life in hospital after taking a substance at a festival in Co Wicklow.

He had attended an event last month but was taken ill and remains in a critical condition in Tallaght Hospital this weekend.

Gardaí believe that the 21-year-od sourced the drugs in the west of Ireland.

It is just two weeks since teenager Jack Downey died. It is suspected he ingested a form of ecstasy at the Indiependence music festival in Co Cork.

A first-year Cork Institute of Technology accountancy student, Mr Downey complained of feeling unwell at the Mitchelstown event, shortly after arriving on site with some friends.

It is suspected he ingested some form of substance, possibly ecstasy or MDMA. He was rushed to CUH but was in a critical condition on arrival.

The Tipperary student (19) died three days later having failed to regain consciousness. His heartbroken parents had maintained a vigil by his CUH bedside.

Speaking at his funeral, his father John said: "He was a fabulous boy - and I am proud to call him my son."

The deaths have been causing major concerns that young people are not aware of the strength or the bad quality of what they are taking.

It means that gardaí are attempting to find the source of the drugs and the people responsible for distributing them.

However, one senior source stressed last night that all drugs are dangerous and young people should avoid them at all costs as the festival season continues and ahead of a new college year.

"There is no such thing as a bad batch as far as senior Garda management is concerned," he said.

"That would imply that there is a good batch of ecstasy or other chemical substances and as far as gardaí are concerned there is no such thing in existence.

"There have been a number of incidents including deaths in recent weeks and while gardaí would be slow to say there is a bad batch of a particular kind of drug in existence, the reality is that people should be aware that taking any of these substances is very dangerous at any time," the source added.